• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.784-793
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• 2005

본 연구에서는 국내 다량우편물 시장의 물량 현황을 고찰하고, 시계열자료를 이용한 물량예측을 목적으로 한다. 특히 다량우편물 수요를 예측함에 있어서 우편 물량의 변화가 경기 변화에 많은 영향을 받는다는 사실과 통상우편의 이메일 대체 현상이 우편 물량 변화에 영향을 미칠 것이라는 판단 하에, 이러한 우편시장 환경의 변화를 고려한 우편 물량 예측을 시도해 보고자 한다.

• The Korean Journal of Applied Statistics
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• v.12 no.2
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• pp.315-323
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• 1999

이 논문에서는 국내 우편통계의 현황에 대하여 간략히 언급하고 있으며 접수 우편물량에 대한 기술통계와 배달 우편물량에 대한 추정을 다루고 있다. 성장곡선모형을 이용하여 접수 우편물량에 대한 예측을 논의하였고 성장곡선모형 중에서 삼차곡선이 매우 잘 적합시키는 것을 확인할 수 있었다. 또한 체신청별 배달 우편물량을 체신청별 접수 우편물량과 마코프 연쇄에서 나타나는 전이행렬을 이용하여 추정하였으며 이는 표본이 비추정의 기본 개념과 일맥 상통함을 발견하였다.

• Journal of Korea Port Economic Association
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• v.28 no.4
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• pp.193-207
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• 2012

The of purpose of this study is to predict export and import container volumes using a Decision Tree analysis. Factors which can influence the volume of container cargo are selected as independent variables; producer price index, consumer price index, index of export volume, index of import volume, index of industrial production, and exchange rate(won/dollar). The period of analysis is from january 2002 to December 2011 and monthly data are used. In this study, CRT(Classification and Regression Trees) algorithm is used. The main findings are summarized as followings. First, when index of export volume is larger than 152.35, monthly export volume is predicted with 858,19TEU. However, when index of export volume is between 115.90 and 152.35, monthly export volume is predicted with 716,582TEU. Second, when index of import volume is larger than 134.60, monthly import volume is predicted with 869,227TEU. However, when index of export volume is between 116.20 and 134.60, monthly import volume is predicted with 738,724TEU.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.794-801
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• 2003

As it is important to measure the degree of the deterioration and predict service life caused by chloride in concrete structure the methods of measuring chloride in the concrete is raised important problems. This study is to set a new standard for using of the colorimetric method through grasping the character of the colorimetric distinction method, and measuring the chloride content at the place discolored. Also, to predict chloride content around embeded bar and time reaching limit chloride concentration through measuring the chloride content of concrete surface by colorimetric distinction method and this study presents the new concept of concrete degradation and diagnosis of the durability by salt damage. According the results, it is possible to use colorimetric distinction method as simplified measurement to measure the fixed quantity of the chloride concentration. What is more, it would make calculation of concrete surface chloride had a wide fluctuation at the general environment extended. Also, it would be make estimating durability of reinforced concrete structures applied to the basic data.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.79-92
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• 2011

Quantity take-off is one of the critical tasks that determine the cost of a construction project, and its result should be accurate and reliable. BIM-based quantity take-off is a very attractive process for practitioners since the quantity take-off can be done automatically in a fast and accurate way. However, the result of BIM-based quantity take-off can be varied depending on how BIM was modeled. As a project progresses, more detailed design information is getting available, and it can be expected that the degree of completeness and accuracy for the BIMbased quantity take-off is going to be improved as well. However, when estimation is performed at each stage of a project life-cycle, there is no way to measure or forecast how accurate of the quantity take-off result from the BIM data given at the current stage. Therefore, this research derived factors that affect the BIM-based quantity takeoff and developed a methodology and framework to measure and forecast the completeness of BIM-based quantity take-off. The measurement framework and index that are proposed by this research was verified and validated for their consistency and feasibility through six pilot projects.

• Korean Journal of Construction Engineering and Management
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• v.12 no.1
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• pp.133-140
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• 2011

Recently, the demolition industry is becoming more important than ever for formulating reuse and recycling of a construction waste with the current trend in pursuing a sustainable development. As considering the situation of a domestic housing construction and an existing house, a scale of a demolition market is expected to increase continually. Therefore, for a sustainable development, it is needed to forecast and manage rightly the demolition waste producted in a demolition phase. But, because most of a demolition company is very small and the investment in a technology development is not enough, the effort to develope a system and to make a standard for managing righly a demolition waste is also not sufficient. Therefore, this study develops a system to automatize quantifying a demolition waste. This system makes it possible to manage the planning of demolition works and the quantifying, disposal, reusing and recycling of a demolition waste in one system by integrating all the activities related with demolition works. 3D drawings of each element for demolition works will manage by being linked to its schedule for visualizing 3D object. Also, this study presents methods for quantifying easily a demolition waste by using 3D object.

• Korean Journal of Construction Engineering and Management
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• v.21 no.3
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• pp.48-56
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• 2020

Prediction of construction cost in the planning stage that provides basic information for feasibility study, budgeting, and planning is an important factor for successful project execution. In this study, a prediction model was developed for the purpose of improving the accuracy of estimating the construction cost of Hanok in the planning stage. The cost of this model is estimated by two methods. First, the cost of wood work, which accounts for the largest portion of the total construction cost, is estimated by calculating the approximate quantity under various conditions (structure type, roof type, plane type, etc.). Second, the cost of the rest work sections except the wood work is estimated by using the unit cost model. The predictive model was verified by two case projects, and the error rate of total construction cost was -4%(case 1) and -6%(case 2). These results showed an error rate in the range that can be applied to practice in the planning stage.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.681-688
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• 2022

In this study, the process of drone photography, automatic volume calculation, total floor area conversion, and waste calculation was constructed as a QGIS plug-in to predict the demolition waste (DW) generated in an aged area where drawing information or building information is uncertain. Through a case study, the high consistency between the automatically calculated volume using the drone and the BIM volume based on the field measurement was confirmed. Field application was carried out for the planned demolition work site, and the consistency between the drone-based volume and the actual measurement-BIM-based volume was reconfirmed. The waste generation unit was applied and the amount of DW was calculated by setting the floor height and building type, and the entire process was completed within 6 hours. Although the difference between building information and building objects through drones occurred according to the setting of temporary structures, loads, and floor heights, it was found that the actual amount of DW was generated more than the initial estimate. It is expected that measures to improve the accuracy of volume and floor area conversion will be required through case studies in the future.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.939-942
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• 2003

본 연구과제는 건설업체의 현재 문제점은 각 업체별로 상이한 분류 및 식별코드체계를 사용, 품목표기방식, 속성 포맷의 불일치, 용어와 단위의 불일치, 현 업계에서 사용하는 코드 분류체계는 호환이 되지 않고 국제적으로 사용할 수 없는 부적합한 실정이다. 따라 기존의 통합정보시스템과 별개로 관리 운영이 이원화되어 오던 각종 건설정보를 건설CALS/EC 핵심기술을 적용하며 건설표준 ERP 템플릿시스템을 개발 할 목적으로 한다. 따라서 본 연구에서는 건설표준 ERP 템플릿시스템과 건설통합분류체계의 표준코드의 연계로 건설CALS/EC 핵심기술이 적용된 건설표준ERP(통합DB)를 구축과 건설공사의 물량산출 데이터의 체계화된 물량예측과 물량공정의 통합화와 설계정보, 시공정보 및 관리유지정보의 연계하여 그리고 현장관리 및 원가관리정보의 통신망접속으로 건설통합정보를 제공한다.

• The Korea Swine Journal
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• v.18 no.3 s.199
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• pp.64-65
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• 1996